Implement kCTF strategy

This implementation is pretty scuffed, but its more exploratory than anything else.

example-app/server/api/pow/challenge.post.ts

@@ -4,12 +4,13 @@ import * as z from 'zod';
 import { outstandingChallenges } from '~~/server/utils/pow';
 
 const challengeSchema = z.object({
-    challenge: z.string(),
-    nonce: z.string()
+    challenge: z.string().startsWith("s."),
+    solution: z.string().startsWith("s.")
 })
 
 // post handler that takes in the challenge, and the nonce
 export default defineEventHandler(async (event) => {
+    console.log(await readBody(event));
     const body = await readValidatedBody(event, challengeSchema.safeParse);
 
     if (!body.success) {
@@ -19,19 +20,25 @@ export default defineEventHandler(async (event) => {
         })
     }
 
-    let target = body.data.challenge;
-    let nonce = body.data.nonce;
+    let { challenge, solution } = body.data;
+
+    const outstanding_challenge = outstandingChallenges.get(challenge);
+    if (outstanding_challenge === undefined) {
+        throw createError({
+            statusCode: 400,
+            statusMessage: 'Challenge not found'
+        })
+    }
 
     // check if the challenge is valid
-    let challenge_valid = await validate_challenge(outstandingChallenges.get(target)!.challenge, {
-        challenge: target,
-        nonce: nonce
-    });
+    const challenge_valid = await validate_challenge(outstanding_challenge.challenge, solution);
+
+    console.log("CHALLENGE VALID", challenge_valid);
 
     if (challenge_valid) {
         // clear the challenge
-        clearTimeout(outstandingChallenges.get(target)!.timeout);
-        outstandingChallenges.delete(target);
+        clearTimeout(outstandingChallenges.get(challenge)!.timeout);
+        outstandingChallenges.delete(challenge);
 
         return {
             message: 'Challenge solved'